Sorry to say but the only real way to free up a significant amount of Other space is to hard reset the phone. My Other was 3.48GB then I reset and after setting it all up the exact same way my other was 2.14GB. So there was 1.34GB of wasted storage. Not important "app data" or anything my phone needed. Legit wasted storage. Clearing IE history might get you 500MB. If you downloaded maps, delete those. This issue with Other eating up free space is a huge problem and I wish Microsoft would address it. Or if someone came out with a file cleanup app, that would be amazing.

Microsoft really needs to fix this mess... On my 920, I had 6GB consumed while only have 1GB in App Data and 1.5GB of Music. No device should use 6GB in "Cache".. This is clearly going to be a major problem for people who have 8GB of storage on their devices.. iOS, Android, BB, MeeGo etc are all able to handle cache without it consuming a majority of the devices memory.. This is clearly poor coding that Microsoft needs to sort out asap.